Microsegmentación de la demanda urbana: técnicas innovadoras en la provisión de servicios públicos urbanos

Peer Reviewe

Mining ancient microbiomes using selective enrichment of damaged DNA molecules

The identification of bona fide microbial taxa in microbiomes derived from ancient and historical samples is complicated by the unavoidable mixture between DNA from ante- and post-mortem microbial colonizers. One possibility to distinguish between these sources of microbial DNA is querying for the presence of age-associated degradation patterns typical of ancient DNA (aDNA). The presence of uracils, resulting from cytosine deamination, has been detected ubiquitously in aDNA retrieved from diverse sources, and used as an authentication criterion. Here, we employ a library preparation method that separates molecules that carry uracils from those that do not for a set of samples that includes Neandertal remains, herbarium specimens and archaeological plant remains

Memorias y tradición oral afroecuatoriana de Nueva Loja

La provincia de Sucumbíos, creada en 1989, nació con la presencia de nacionalidades indígenas, población mestiza y pueblo afroecuatoriano; su vertiginoso aumento poblacional y desarrollo económico tienen que ver con la actividad petrolera, agrícola y comercial de la zona

Influence of germination on lectin in Lens culinaris seeds

The effect of germination conditions on the lectin of Lens culinaris var. Magda 20 seeds was studied. The seeds were germinated at 20 °C under different conditions of watering and light and for different periods of time. The seed lectin was assayed by haemagglutination and quantified by competitive ELISA. Changes in lectin content during germination were also monitored by SDS-PAGE and immunoblotting. Haemagglutinating activity and lectin content in the seeds were not changed during the first three days regardless of the conditions of the germination. However, lectin concentration was significantly higher after six days of germination; relative lectin levels being particularly high when germination was carried out in the light and with daily watering. The results of SDS-PAGE and immunoblotting have also shown that the lectin was not degraded during the first six days of germination however, other storage-proteins were broken down by proteolysis

Counting the photons : determining the absolute storage capacity of persistent phosphors

The performance of a persistent phosphor is often determined by comparing luminance decay curves, expressed in cd/m(2). However, these photometric units do not enable a straightforward, objective comparison between different phosphors in terms of the total number of emitted photons, as these units are dependent on the emission spectrum of the phosphor. This may lead to incorrect conclusions regarding the storage capacity of the phosphor. An alternative and convenient technique of characterizing the performance of a phosphor was developed on the basis of the absolute storage capacity of phosphors. In this technique, the phosphor is incorporated in a transparent polymer and the measured afterglow is converted into an absolute number of emitted photons, effectively quantifying the amount of energy that can be stored in the material. This method was applied to the benchmark phosphor SrAl2O4: Eu, Dy and to the nano-sized phosphor CaS: Eu. The results indicated that only a fraction of the Eu ions (around 1.6% in the case of SrAl2O4: Eu, Dy) participated in the energy storage process, which is in line with earlier reports based on X-ray absorption spectroscopy. These findings imply that there is still a significant margin for improving the storage capacity of persistent phosphors

Differential loss of effector genes in three recently expanded pandemic clonal lineages of the rice blast fungus

BACKGROUND: Understanding the mechanisms and timescales of plant pathogen outbreaks requires a detailed genome-scale analysis of their population history. The fungus Magnaporthe (Syn. Pyricularia) oryzae-the causal agent of blast disease of cereals- is among the most destructive plant pathogens to world agriculture and a major threat to the production of rice, wheat, and other cereals. Although M. oryzae is a multihost pathogen that infects more than 50 species of cereals and grasses, all rice-infecting isolates belong to a single genetically defined lineage. Here, we combined the two largest genomic datasets to reconstruct the genetic history of the rice-infecting lineage of M. oryzae based on 131 isolates from 21 countries. RESULTS: The global population of the rice blast fungus consists mainly of three well-defined genetic groups and a diverse set of individuals. Multiple population genetic tests revealed that the rice-infecting lineage of the blast fungus probably originated from a recombining diverse group in Southeast Asia followed by three independent clonal expansions that took place over the last ~ 200 years. Patterns of allele sharing identified a subpopulation from the recombining diverse group that introgressed with one of the clonal lineages before its global expansion. Remarkably, the four genetic lineages of the rice blast fungus vary in the number and patterns of presence and absence of candidate effector genes. These genes encode secreted proteins that modulate plant defense and allow pathogen colonization. In particular, clonal lineages carry a reduced repertoire of effector genes compared with the diverse group, and specific combinations of presence and absence of effector genes define each of the pandemic clonal lineages. CONCLUSIONS: Our analyses reconstruct the genetic history of the rice-infecting lineage of M. oryzae revealing three clonal lineages associated with rice blast pandemics. Each of these lineages displays a specific pattern of presence and absence of effector genes that may have shaped their adaptation to the rice host and their evolutionary history

Valoración Del Desempeño Del Proceso De Reparaciones En Un Sistema De Distribución De Electricidad

Este artículo presenta una metodología para valorar el desempeño del proceso de reparaciones en un sistema de distribución local de electricidad (SDL), la cual modela los recursos para reparación y su logística como un sistema de colas cuya entrada y cuyo servicio son procesos estocásticos puntuales estacionarios o no estacionarios. El cálculo de los índices de desempeño del proceso se realiza mediante un procedimiento de simulación de Montecarlo secuencial. Luego de analizar un SDL típico colombiano, se encontró que el tiempo de espera es el índice que mejor refleja el desempeño del proceso de reparaciones

School Feeding Programs in Middle Childhood and Adolescence

Almost every country in the world has a national school feeding program to provide daily snacks or meals to school-attending children and adolescents. The interven- tions reach an estimated 368 million children and ado- lescents globally. The total investment in the intervention is projected to be as much as US$75 billion annually (WFP 2013), largely from government budgets. School feeding may contribute to multiple objectives, including social safety nets, education, nutrition, health, and local agriculture. Its contribution to education objectives is well recognized and documented, while its role as a social safety net was underscored following the food and fuel crises of 2007 and 2008 (Bundy and others 2009). In terms of health and nutrition, school feeding contributes to the continuum of development by build- ing on investments made earlier in the life course, including maternal and infant health interventions and early child development interventions (see chapter 7 in this volume, Alderman and others 2017). School feeding may also help leverage global efforts to enhance the inclusiveness of education for out-of-school children, adolescent girls, and disabled persons, as called for in the Sustainable Development Goals (see chapter 17 in this volume, Graham and others 2017). Although the Disease Control Priorities series focuses on low- and middle-income countries (LMICs), evidence from high-income countries (HICs) is included because of the near universality of school feeding and the insights that inclusion can provide as economies develop. For example, the design of school feeding in countries under- going the nutrition transition 1 may provide some lessons on how to shift from providing access to sufficient calo- ries to promoting healthful diets and dietary behaviors for children and adolescents (WFP 2013). Agricultural development has increasingly gained attention. It is clear that to enable the transition to sus- tainable, scalable government-run programs, the inclu- sion of the agricultural sector is essential (Bundy and others 2009; Drake and others 2016). Accounting for the full benefits of school feeding through cost- effectiveness and benefit-cost analysis is challenging, similar to other complex interventions, but undertaking this accounting is critical for assessing the tradeoffs with competing investments. This chapter reviews the evidence about how school feeding meets these objectives and provides some indi- cation of costs in relation to benefits. The costs of the intervention are well established; estimates that encompass all the benefits of school feeding are more challenging. The benefits must be quantified and translated to the same unit to allow for aggregation. Moreover, how school feeding interventions are designed and implemented varies significantly across countries. Given that delivery of school feeding often involves multiple sectors, common policy frameworks and cross-sectoral coordination are required to achieve maximum benefit (Bundy and others 2009). Several other chapters in the volume highlight school feeding. These include chapter 11 (Lassi, Moin, and Bhutta 2017), chapter 20 (Bundy and others 2017), chapter 22 (Plaut and others 2017), and chapter 25 (Fernandes and Aurino 2017)